1. Field of the Invention
The present invention relates to an information network technology and a mobile communication terminal, and more particularly to an authentication technology for an authentication server performing shared control of a file based on the position information of each terminal and file server, in an environment where a plurality of terminals and file servers which have a sharable information resource, such as a file, are connected to be a network via cable or radio transmission.
2. Description of the Related Art
Terminals and file servers are connected via a network to share information. In a radio network connection, the terminals and file servers can establish communication via access points of a radio LAN using radio waves.
However, the radio waves reaching range is undefined, so it is possible that an unexpected terminal which exists in the radio waves reaching range connects to the network, and a user with ill intent may operate the terminal and obtain information from another terminal or file server without leaving any evidence of their presence.
In the above mentioned prior art, where the range in which the radio communication is possible is not restricted, the case when an unexpected or unauthorized terminal which exists in the radio waves reaching range is connected to the network is not considered, and a leak of information may occur, which has been a technical problem.
Japanese Patent Laid-Open No. 2000-215169 discloses a technology where a specified data set is assigned for each access point to the LAN of the radio terminal, so that the specified data set is accessed automatically each time an access point changes, but the position information used for identifying the position of this radio terminal is only the position information of the access point. Therefore it is possible, for example, that an access point is assigned to each room of a building and an accessible data set can be switched each time the user moves out of each room, but access from outside the building cannot be identified, where the above mentioned technical problem, such as information leakage, is still unresolved.